105P - Detection and clinical significance of circulating tumour cells in patients with rectal cancer

Background

Rectal cancer is one of the most common causes of cancer-related deaths worldwide. Circulating tumor cells (CTCs) are rare aneusomic cells that detach from the primary solid tumors and enter the circulation, and can initiate metastasis. Detection of CTCs in liquid biopsies is a promising strategy for diagnosing, monitoring the relapse and metastasis, and evaluating cancer prognosis and therapy. However, CTC detection in patients with rectal cancer is limited in routine clinical practice. The aim of this study was to elucidate the role of CTCs in patients with rectal cancer.

Methods

A total of 142 patients with rectal cancer were enrolled. CTCs were measured in the peripheral blood (preoperatively, immediately postoperative, day 1 and 7 postoperatively) and inferior mesenteric vein (intraoperatively), usingthe CTCBIOPSY® System (YZYBIO Company, Wuhan, China). General information, initial diagnosis and the integrated pathological information of all participants were recorded. Data Analysis was performed using the Chi-square test, with 95% confidence intervals (95% CIs) as the threshold for statistical significance.

Results

CTCs were detected (≥1 CTC per 5ml blood) in the blood preoperatively more frequently in patients with a higher grade of TNM stage (c2=7.317, P = 0.048) and there was a trend of association (c2=6.457, P = 0.012). CTC detection in the blood was significantly associated with T stage (c2=12.912, P = 0.005) and N stage (c2=17.587, P < 0.001) preoperatively. It proved that age and gender were uncorrelated variables with CTC detection. Compared with CTC detection preoperatively, postoperative CTCs are firstly increased and then decreased.

Conclusions

CTC detection is closely related to TNM stage in patients with rectal cancer, and so it may be a way to predict clinicopathological stage by detecting CTCs. The postoperative CTCs are potential biomarkers for rectal cancer prognosis but needed to be verified in more studies.

Clinical trial identification

NCT02955173; Pre-results.

Editorial acknowledgement

Legal entity responsible for the study

Qilu Hospital of Shandong University.

Funding

Ministry of Science and Technology of China.

Disclosure

The author has declared no conflicts of interest.